This invention relates to a differential assembly for use in an axle, and more particularly, the invention relates to a ring gear and differential case used in a differential assembly.
Differential assemblies are commonly used in axles and other rotational transmission devices to provide relative rotation between shafts arranged along a common axis. The differential assembly typically receives rotational input from a drive shaft transverse to the common axis. The rotational input is transmitted through the differential assembly by a ring which is secured to a differential case. The differential case supports the ends of the shafts and the gears necessary to permit relative rotation of the shafts.
The ring gear is typically secured to differential case using numerous bolts, nuts and washers, which add costs and weight to the differential assembly. The ring gear and differential case are manufactured separately and secured to one another, which in part is necessitated by the different materials usually utilized to construct each of the components. The ring gear is typically constructed from a forged steel to withstand the large input forces transmitted through the drive shaft, and the differential case is typically constructed from a ductile iron or cast steel.
One proposed solution to eliminate the fastening components of the prior art was to manufacture the ring gear and differential case as a single unit from forged steel. However, utilizing forged steel for the entire differential assembly may increase the overall weight of the assembly because of the increased density of forged steel as compared to ductile iron. Moreover, forging such a large component increases the cost of the differential assembly. Therefore, what is needed is a method and apparatus of securing the ring gear to the differential case.